Monday, 25 March 2013

70# @ V nearly 28"

I've teased it back and had a couple of test shots at 28" draw with my heavier arrows using my tillering string.
It feels good. Next step is to make a proper string.
It would have been easy to screw up while tillering the last couple of inches.
The tips weren't working much and I just went over the belly lightly with a rasp and tapered the tips into the nocks a bit more.
I got it on the tiller and took the rope off the winch so I could lean back on the opposite wall (where the camera is mounted) and pull back and forth on the rope. As it was approaching the 70# I could see the left limb was now working much too hard at the tip and was a whisker soft compared with the right.
I marked W on the weak section and scribbled a line where i needed to take off a little wood mid limb.
A little light rasping near the middle of the left limb and some all along the right improved the balance and got me back to almost 28 inches at 70#.
If you make the video full screen and stop it at full draw you may see what I mean. On the other hand you may think it's fine, such are the subtleties of tillering.

I think the left limb has a tighter curve than the right especially in the outer half. I'll get the whole limb working a little better before risking taking it beyond 28". Having the stiff spliced section in the centre slightly confuses the issue from my usual arc of a circle tiller shape.
Further explanation of the shape:-
It looks slightly 'square' to me e.g flat in the centre and then a corner and the tips coming down too hard, sort of whip tillered. Mind there's half an inch to go really, so just easing off the right limb a bit and some off the inner third of each should do the job.

video
It's rather nerve racking as it's a very good bow at 28" with no set, so I'm going to be V cautious about taking it further. I'll shoot it in at 28" and gradually work it back keeping an eye on the tiller of course.

It's easy top get nearly there and think all the hard work is done.
A young guy was over at the weekend to split an Ash log, we sawed it in the end as it was fairly small and it seemed better to end up with two good staves rather than risk twist or wander off and end up with none.
He was telling me how he had a Hazel bow blow up at about 25", but he felt he'd probably rushed it. That's just the point I'm making, take your eye off it for a moment and it runs away from you.
He has a very long draw (about 31") and asked for suggestions... well all I could offer is to start with a much longer stave or, with shorter primitive style bows shoot native style by drawing up in front of your face. The Ash log was 9' long, so he has plenty to play with!

Tillering is tricky as you need one eye on the draw weight, one on the draw length and one on the curve of the bow limbs. Take your eye off any one of them at your peril!

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